The present invention relates to a process for the preparation of flexible and free standing conducting polyaniline film. The thickness of the film can be tailored
Hitherto conducting polyaniline has been reported as a free standing conducting film having a electronic conductivity of 0.1 to 1 S/cm (Patent applicationxe2x80x94CSIR Ref. No. NF 290/00).
Film formation property is not observed when unfunctionalised dopants like hydrochloric acid, sulphuric acid, acetic acid and various other mineral and organic acids are used as primary dopants.
Copending patent application (C.S.I.R Ref NF 290/00) discloses a process to obtain the free standing conducting polyaniline ≈0.1 to 1 S/cm. The drawback of the process described in NF 290/00 is that the free standing film is obtained by casting polyaniline solution in organic solvents like chloroform, benzene, xylene and toluene which are difficult to recover. Also, the letting out of solvents in the atmosphere leads to pollution and secondly electronic conductivity lies in the range of 0.1 to 1 S/cm, which is not enough for many applications,
Flexible and free standing conducting polymer film has application in the shielding of electromagnetic interference [EMI], conducting wires, as a thin film for batteries chemical sensor, anti-static agent, zebra connectors for multi-point connections and in many other electronic applications. It is therefore important to develop a process for the preparation of a flexible and free standing conducting polyaniline film.
The main object of the present invention is to provide an improved process for the preparation of flexible and free standing conducting polyaniline film around 10 S/cm and to avoid organic co-solvents to obviate the drawback as detailed above.